# -*- coding: UTF-8 -*-
from typing import List
from leetcode_helper import TestcaseHelper, SolutionBase


class Solution(SolutionBase):
    def __init__(self):
        self.dfs_dict = {}

    # 解题的方法，命名和Leetcode的保持一致即可
    def process(self, nums, curr_index, target, sum):
        key = str(curr_index) + '_' + str(sum)
        value = self.dfs_dict.get(key, None)
        if value:
            return value

        if curr_index == len(nums):
            if sum == target:
                self.dfs_dict[key] = 1
                return 1
            else:
                self.dfs_dict[key] = 0
                return 0
        else:
            next_index = curr_index + 1
            left = self.process(nums, next_index, target, sum + nums[curr_index])
            right = self.process(nums, next_index, target, sum - nums[curr_index])
            self.dfs_dict[key] = left + right
            return left + right

    def findTargetSumWays(self, nums: List[int], target: int) -> int:
        self.dfs_dict.clear()
        return self.process(nums, 0, target, 0)


if __name__ == '__main__':
    solution = Solution()

    # 按照leetcode的题目说明，将基本的test case填入
    # 每条case的最后一个元素是正确的结果，即期待的结果
    # 使用元组来保存输入的数据，期待的结果
    testcases = [
        ([1, 1, 1, 1, 1], 3, 5),
        ([1], 1, 1)
    ]

    for case_item in testcases:
        # 获取测试用的case和期待的执行结果
        input1 = case_item[0]
        input2 = case_item[1]

        expect = case_item[len(case_item) - 1]

        exec_result = solution.findTargetSumWays(input1, input2)

        # 判断执行结果，输出提示信息
        check_result = solution.check_result(expect, exec_result)
        TestcaseHelper.print_case(check_result, case_item, exec_result)

